O.Thetford, P.Gray German Aircraft of the First World War (Putnam)

Otto C II
  This machine was the last type built before the firm went into liquidation. It was a conventional two-seater of wood and fabric construction. Engine, 160 h.p. Mercedes D III. Span, 13.4 m. (43 ft. 11 5/8 in.). Weights: Empty, 829 kg. (1,823 lb.). Loaded, 1,329 kg. (2,924 lb.).

J.Herris Otto, AGO and BFW Aircraft of WWI (A Centennial Perspective on Great War Airplanes 37)

Otto C.II

  The Otto C.II was the final Otto design to be built. To be acceptable to the Prussian air service it was a tractor biplane that was more refined than earlier Otto designs.
  The Otto C.II was a conventional two-bay tractor biplane with either 160 hp Mercedes D.III or 150 hp Benz Bz.III with leading edge radiator and over-wing gravity tank. Empty weight was 829 kg; gross weight was 1329 kg, and wing span was 13.40 meters.
  Although it was a C-type, the photos showing armament show a machine gun mounted in a turret in the front cockpit for the observer with pilot in the back cockpit (like the Aviatik C.I, Alb. C.IV, and LVG C.III). The Frontbestand shows no Otto C.II aircraft at the front and it appears the small number of C.II aircraft built in 1915-16 were used for training. Otto C.II production apparently came to an end with the collapse of the Otto company and its reorganization into BFW.
  At least 12 C.II aircraft were built in the first batch and perhaps as many as 12 in the second batch. The second batch may have been completed with Albatros C.III(Bay) aircraft.


Otto C.II Production
  Serials Notes:
  C.3581-3592/15 12 aircraft
  C.204/16, etc. 12 aircraft?
  Batch 2 perhaps filled with Alb. C.III(Bay).

Журнал Flight

Flight, November 12, 1915.

THE OTTO BIPLANES.

  OF the German aeroplane constructors who have paid special attention to the development of the all-steel machine few have met with greater success than have the Otto works at Munich. In the accompanying illustrations are shown two types of fuselages which are similar as regards construction, but differ in that one is designed for a stationary engine, whilst the other is of a slightly different form in front to take a rotary motor. One feature common to all Otto machines is the employment throughout of seamless chrome nickel steel tubes for longerons and struts of the fuselage. The attachment of the struts to the longerons is by means of special steel clips, which grip the various members without piercing them, a form of construction which has the further advantage that it facilitates replacement in case of fracture.
  Attachment of the wings to the fuselage is by means of similar steel clips so designed that it is possible to slide the wings a short distance along the longerons so that a heavier or lighter engine may be fitted and the balance of the machine preserved by shifting the wings slightly backwards and forwards. In addition to this adjustment the angle of incidence can be altered to suit various purposes. In the machines shown both these adjustments are carried out when erecting the machine, but, according to information available, later types will be fitted with the necessary levers for carrying out this operation while in the air, an improvement that has no doubt been rendered effective by this time.
  Wing spars as well as interplane struts are, like the fuselage, made of steel tubes, the struts, needless to say, being of streamline section, and bracing is effected by means of stranded steel cables. The engine, in the case of the stationary motor, is mounted on stout ash bearers supported from the longerons of the fuselage; while in the machine designed for a rotary engine the bearers are more or less of a similar type to that employed on British machines.
  Although being made of steel throughout, the Otto biplane is said to be lighter than one of the same size made of wood, and the factor of safety in the wings is stated by the makers to be 8.
  A chassis of the usual simple type found in the majority of German military machines is fitted, the material used being streamline steel tubes for the struts and a tubular axle slung by rubber bands. Quickly detachable steel clips secure the chassis struts to the lower longerons of the fuselage, and the chassis can, like the wings, be moved slightly backwards and forwards to obtain perfect balance on the ground for engines of different weight.
  The older machines were fitted with 100 h.p. Mercedes engines, but in view of the exceptional facilities for changing over, it appears highly probable that the latest ones have engines of 150 h.p. or more, which, in conjunction with the variable angle of incidence, should give a machine of more than ordinary utility.